Fix return zero size String array with empty String array in delimiitedListToStringArray of StringUtils

Prior to this commit, zero size String array returns if StringUtils.delimitedListToStringArray is called with parameter empty String ("")

I think, after call StringUtils.delimitedListToStringArray("", ",", null);

it should return one size String array -> [""]

but it returns zero size String array.

StringUtils.delimitedListToStringArray(null, ",", null) & StringUtils.delimitedListToStringArray("", ",", null)

should returns differently. However there are same results.

There's no logic for empty String(""), but just is for null parameter.

I added if statement for "" parameter. The result will be one size String array.

And also in SPR-11126, the issue will be solved.


Issue: SPR-11126